I just got my CD63 mkII and certainly impressed with the sound of it coupled with my arcam delta 290 amp and monitor audio b2 speakers, but I WANT MORE !!!!

The mods listed by simon tY are pretty much what i want to do. I'm ok at soldering, and am preactising at the moment by removing DC output caps, bypassing output buffers, and replacing the op-amp with an lt1364, all on my emu 0404 soundcard. I have all the tolls needed to solder, and im ok at this soldering malarky too, but not too hot yet on SMT soldering.

Hi Adam,

It sounds like you're chomping at the bit to get stuck in, and rightly so.

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Right the mods:

- Firstly im going to fill the 4 feet with blu-tac, and use either some car sound dampening bitumen pads, or the isolation stuff off audiocom to dampen the insides of the player.

Damping the insides should help the sound, but the feet really ought to be replaced with hard cones. It's my experience that this provides a more lifelike sound than soft feet (more solid and tuneful bass especially).

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- (1. removal of dc blocking caps*). I have the service manual, but am not sure which caps are the dc blocking caps, and what is is the safe DC offset that can be allowed when the caps are removed + bypassed ??

These caps block DC from going to the amp, as such they are near the output sockets - C655, C657 (left channel) and C656, C658 (right channel). I wouldn't worry too much about the DC, but you should measure it - just stick multimeter probes into the socket and turn the player on. Tell us what you get and someone will comment. DC is almost certainly dealt with in your amp though, making the caps ENTIRELY superfluous. They ruin the sound, again it's the bass more than anything.

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- (2. add on clock with totally dedicated psu). I have seen the cheap audiocom superclock 2 on ebay for £70 and was wondering if i should get one of their upgrade kits including the clock and supregs ranging from £100 - £120 - £130. Are the upgrade packs worth it etc etc ????
Also, is it easy to fit the new clock, and is it really necessary for another PSU, as i cant be bothered to make an external one?

Audiocom Superclock2 for £70 is good value, as it used a proven design, uses nice parts, and it's ready made for you. I think if you don't want to spend too many hours poring over schematics and learning to build circuits just buy their parts because they seem nice and will certainly do the job.

Ok, IME, a clock upgrade like this takes the player from 5/10 to 6/10, then a psu takes it to 7.5/10 (only relatively speaking!). It is absolutely necessary to feed it good power, and I say 'dedicated' because it's known that the voltage rails in the CD63 are fully cr@p - this would explain my listening results.

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- (3. op-amps to opa627 or other top notch solution). Will i need a/some browndogs for op-amp replacement, and how many op-amps will i need? also where about are they on the board ?

You'll need 'dawgs for using OPA627, and as these are single op-amps replacing doubles you'd need 4. I would suggest sockets be installed for safety, and convenience for comparing. Try OPA2134, LM6172, AD8620(?) and whatever else people routinely suggest. Those 3 are doubles and drop straight in with no adapters. You may prefer one over another. It's absolutely mandatory to bypass the psu pins of the op-amps (can do that under the sockets - I did) with electrolytic caps (33uF/50v Panasonic FC worked for me). If you don't understand what I mean I can show you pics of what that looks like.

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finally - (5. bypassing hdam) This seems fairly simple, and involves removing a few things and bridging the gaps with some wires. btw. what sort of wire should i use for internal connections, and where can i get it from?

The wire doesn't matter too much. Just as long as it's not silver plated.

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Very final question. Are these mods only for the analog circuit, or is it worth just using the cdp as a transport and buying a nos dac or monica2 dac??? Would the mods listed above be bypassed with a DAC or will they make the player sound better than getting a DAC ??

These mods are for the analogue parts, and the DAC used is generally considered to be very good, so it's not worth making the player a transport only. An old player surely isn't the best for that job anyway. The player can sound stunning, so don't bother with a separate DAC!

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sos for all the questions, but im a newbie. Will it be better for me to start a new' help adam mod his cd63) thread rather than clogging this one up?

Thanks all
ad

Well, hopefully I've answered most of what you asked. No need for a new thread IMO.

What Simon says is pretty spot on. I would do each mod at a time though!

You need to hear what mod has done what. Its gives you a better insite into the player and what effect different bits do.

Here is a basic guide I use when modding players

1) Output caps bypassed - little bit more open sound and much better bass (and remove muting transistors)
2) Op amps - fit something like a OPA2134 first, you wont beleive the difference. You can at a later date change for 627 on browndogs etc to push the sound further.
3) Clock - I have that Audiocom clock from ebay - bargain. Dont worry about making a dedicated supply just yet unless you are confident.
4) HDAM bypass - a must do mod once the op amps are changed.
5) change all the resistors around the opamps to 0.1%tol types and all the blue se caps to silver mica.

6) Work on a way of seperating all the 5V rails to the DAC and the Decoder. You have Analogue 5v , digital 5v and clock ref 5V to these. Even using 3x cheap 7805 will give benefits (trust me I have tried it)

I'm gathering parts now for the Thorsten Loesch valvestage, the one in the first link. I didn't come across the other one yet, thanks.

I'm going to give this circuit a try first, and see if I like the (opamp-less) results. I chose it because it is fairly simple and uses only one tube per channel. I'm going to use a simpler PSU initially.

In theory it is possible to use any tube with considerably lower B+. But the characteristics will not be that nice in that region. It will also be difficult to draw some current with that low anode voltage.
There are tubes that are specially made for low-voltage (battery) use, that could be an option. I don't know any typenumbers though.

It's not very difficult to build a PSU that can deliver +240V/20mA, and I'll need another tranny anyway. There's a transformerbuilder nearby where I live, and he can make me a small 200V/50mA + 6,3V/1A tranny just like that (for the dutch people: yep, it's Automatic Electric Europe). I'm very lucky .

If you are using bitumen damping pads, don't go to Halfords or a shop which specialises in in-car entertainment. Go to you local car shop.
Halfords were charging £10+ for a 12"x12" sheet as were the ice shops. My local shop charged £3.75 for 12"x 24" sheet!

Andy

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If it ain't broke, break it !! Then fix it again. It's called DIY !

Just a few of my tubes for the output.
Type numbers to look out for are 6BF7, 6BF7W, 6021
The advantage is that these can be hardwired in place an can also lie flat. The ECC88 can also be used at low B+.

Andy

Hi Andy,

Those are nice little ones! They have suitable spec's too, max. 110V, not too high gain. If you use them in Thorsten's circuit you won't even have to change much, just lower the B+ a bit, since the voltage on each tube will be half B+ approximately.